Numerous products are obtained by assembling a plurality of units, in particular a plurality of layers or sheets. This applies in particular to belts, which are generally formed by using heat to assemble together two solid and continuous bands that are separated by a layer of reinforcing cords.
Whatever the application, the various units are positioned relative to one another prior to being secured together. Several problems can then arise. The prepositioned units may be shifted unintentionally, either before or during assembly, thereby slowing down the fabrication process or fabricating a product that is defective and will need to be rejected. Worse, such an unintended shift of one or more of the units can be difficult to detect during fabrication, and might lead to danger for the user of the final product.
In order to mitigate those problems and make the positioning of the various units before and during assembly reliable, proposals have been made to use pre-assembly means such as clamps or staples. Nevertheless, such means can be difficult to remove, thereby making repositioning very difficult in the event of an error. They can also lead to localized stress zones in the product. They can also be impossible to extract, thereby leaving foreign bodies in the final product.
In certain applications, attempts have been made to use adhesive means for pre-assembly since they are less intrusive. For example, in the field of belts, it is known to apply an adhesive composition to the reinforcing cords in order to hold the two bands placed on either side of them in position.
With such means, it still remains difficult after the event to correct poor positioning of the units. Such adhesive means can be difficult to fabricate given the environmental standards and regulations that need to be complied with. They also present the drawback of easily losing their adhesive properties over time or as a consequence of poor storage conditions.